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# Python – Append according to Kth character

• Last Updated : 02 Sep, 2020

Given a String list, append to String i or j value depending on Kth index value.

Input : test_list = [“geeksforgeeks”, “best”, “for”, “geeks”], K = 2, N = ‘e’, i, j = “@@”, “..”
Output : [‘geeksforgeeks..’, ‘best@@’, ‘for@@’, ‘geeks..’]
Explanation : geeksforgeeks and geeks having similar 2nd occ. value as ‘e’, hence gets appended by “..”.

Input : test_list = [“giiksforgeeks”, “bst”, “for”, “geeks”], K = 2, N = ‘e’, i, j = “@@”, “..”
Output : [‘giiksforgeeks@@’, ‘best@@’, ‘for@@’, ‘geeks@@’]
Explanation : No values with K value ‘e’, all appended by @@.

Method #1 : Using loop

This is brute way to solve this problem, we check for each string’s Kth index, if found to be N, then i value is appended else j is appended.

## Python3

 `# Python3 code to demonstrate working of ``# Append according to Kth character``# Using loop`` ` `# initializing lists``test_list ``=` `[``"geeksforgeeks"``, ``"best"``, ``"for"``, ``"geeks"``]`` ` `# printing string``print``(``"The original list : "` `+` `str``(test_list))`` ` `# initializing K``K ``=` `2` ` ` `# initializing N ``N ``=` `'e'`` ` `# initializing i, j ``i, j ``=` `"**"``, ``"##"`` ` `res ``=` `[]``for` `sub ``in` `test_list:``     ` `    ``# checking for Kth index to be N``    ``if` `sub[K] ``=``=` `N:``        ``res.append(sub ``+` `i)``    ``else` `:``        ``res.append(sub ``+` `j)`` ` `# printing results ``print``(``"The resultant List : "` `+` `str``(res))`
Output
```The original list : ['geeksforgeeks', 'best', 'for', 'geeks']
The resultant List : ['geeksforgeeks**', 'best##', 'for##', 'geeks**']
```

Method #2 : Using list comprehension

This solves this problem in similar manner, just difference being, it’s a shorthand and can be used  as one liner approach to solve this problem.

## Python3

 `# Python3 code to demonstrate working of ``# Append according to Kth character``# Using list comprehension`` ` `# initializing lists``test_list ``=` `[``"geeksforgeeks"``, ``"best"``, ``"for"``, ``"geeks"``]`` ` `# printing string``print``(``"The original list : "` `+` `str``(test_list))`` ` `# initializing K``K ``=` `2` ` ` `# initializing N ``N ``=` `'e'`` ` `# initializing i, j ``i, j ``=` `"**"``, ``"##"`` ` `# shorthand to solve this problem``res ``=` `[sub ``+` `i ``if` `sub[K] ``=``=` `N ``else` `sub ``+` `j ``for` `sub ``in` `test_list]`` ` `# printing results ``print``(``"The resultant List : "` `+` `str``(res))`
Output
```The original list : ['geeksforgeeks', 'best', 'for', 'geeks']
The resultant List : ['geeksforgeeks**', 'best##', 'for##', 'geeks**']
```

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